What determines the appearance and behavior of the Eclipse status line?

I do Android development using Eclipse Indigo. With most of my XML and Java files the status line shows "Writable" and "Smart Insert" and the line and column numbers separated by a colon ":" . But on some files in the same project, these do not appear. I want to see the line and column numbers for all my Java and XML files.

Also, while we're about it, what do "Writable" and "Smart Insert" mean?